Homepage Archive #13

These archive pages are provided in order to make it easier for you to find items that
you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything
on the website is to use the "Search RF Cafe" box at the top
of every page.

No,
it does not dispense electronic candy. A few years ago my daughter
gave me a second-hand Dilbert candy dispenser, but the mechanism
didn't work. It turns out the battery holder was wired backward
from the factory so it could never have worked. Anyway, there is
one part that is especially frustrating to remove
(the
computer front panel), and many people have written to
me asking for details. Have just now received another request, I
decided to add that info to the web page.

RF Cafe Visitor Finds His GreatGrandfather
in 1944 QST Article

One
of the reasons I go to the trouble of posting the old magazine articles
from SQT, Popular Electronics, Electronics World, etc., is to allow
people searching for stories about relatives a better chance of
finding information. A couple days ago the great grandson of a WWII
reconnaissance officer who died in the line of duty. Captain William
H. Graham was a Ham radio operator before the war, holding call
sign W9BNC. The story was told in the July 1944 edition of QST under
the title of "Hams
in Combat - One Life to Give." Read the note sent by his grandson.

Government Is BombardingCitizens with Radiation!

Please, even if you sincerely believe that the
government is bombarding you with radiation in order to control,
maim, or kill you, do not call me. As a former agent of the U.S.
government's National
Unit
for ciTizen
Subduance
(code word: NUTS), all of my communications are constantly under
surveillance, so merely contacting me by telephone, e-mail, Skype,
telegraph, message in a bottle, or smoke signals virtually guarantees
that "they" will find you and increase the attack already underway
against you. For all that is Holy, spare yourself from the personal
torment and hide while you still can! Seriously, four or five people
call me every year wanting to tap into my expertise on RF energy
to help them validate their suspicion - no, wait, absolute certainty
- of currently being the victims of a huge government conspiracy
whereby special frequencies that have been determined to allow mind
control are attempting to turn them into mindless subjects. I just
got off the phone with another such individual. All sound genuinely
friendly and inquisitive regarding some kind of RF principle they
are not totally knowledgeable about, and admit to being new to the
world of radio frequencies. Usually...

RF Engineering ThemeCrossword for 12/30/2012

For
the sake of avid cruciverbalists, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics,
chemistry, physics, and other technical words. You will never be
asked the name of a movie star unless he/she was involved in a technical
endeavor (e.g., Hedy Lamar). This is
the December 30, 2012 puzzle.

Loose Parts Comic'Norse Code"

I've
recommended some tech-themed "Loose
Parts" comics in the past (here
and
here). This one will give you a chuckle, particularly
if you are a CW guy (or gal).

Notable Quote

"I
have an app on my phone that lets me talk to all the people around
me. It shuts the phone off." - Mark Simone, talk show guy

Tales from the Cube:A Dark Story

This
intriguing story of troubleshooting prowess - and luck - will appeal
to people like me who were around in the electronics industry in
the 1970s and 1980s when
CMOS
logic was just coming onto the scene. Everyone loved the low
power aspect of CMOS and rushed head-long into implementation, then
had to put a lot of time into modifying circuits to rectify issues.
A new set of design rules were required. I won't spoil the solution,
but will say after you read this installment of
Tales from the Cube, you will likely recall from decades
ago at least one similar "ah-ha" moment in the lab.

Featured Book: RF andMicrowave Radiation
Safety

RF
and Microwave Radiation Safety, by Ronald Kitchen. A practical handbook
for all involved in electronic design and safety assessment, RF
and Microwave Radiation Safety covers the problems of RF safety
management, including the use of measuring instruments and methods,
radiation hazards and risks resulting from electromagnetic interference,
as well as reviewing current safety standards and the implications
for RF design. The second edition takes into account a wide range
of technical and legislative changes, and has been revised in line
with the latest EU and international standards. Issues raised by
increasing levels of microwave pollution from mobile phones and
other sources are also confronted.

Practical Applicationsof Simple Math

Recognizing
that many people were reluctant to approach the theoretical aspect
of electronics as it applied to circuit design and analysis, QST
(the American Radio Relay League's monthly publication) included
equations and explanations in many of their project building articles.
Occasionally, an article would be published that dealt specifically
with how to use simple mathematics. In this case, the June 1944
edition, we have the second installation of at least a four-part
tutorial that covers resistance and reactance, amplifier biasing
(tubes since the Shockley-Bardeen-Brattain trio hadn't invented
the transistor yet) oscillators, feedback circuits, etc.

IEEE: Engineering inBiology and Medicine

Miracle
inventions in medicine and biology often require the assistance
of electrical engineers to provide an interface for measurement
and/or control. Ingestible and implantable wireless probes and monitors,
wearable brain wave caps, robotic limb replacement and assistance
devices, imaging equipment, and nanotechnology are a few of the
applications requiring an
EE partnership.
Many doctors were first engineers before getting a medical degree,
and as such do their own circuit and/or mechanical and/or software
design. The
IEEE is executing (maybe the wrong verb
to use when addressing medical topics) an awareness effort
to hopefully attract engineers into the field. Some projects have
you working directly with patients and volunteer test subjects,
so if you are one of those fabled non-introverted engineers, this
might be the career course for you.

2013 IEEE RFIC SymposiumCall for Papers

Plans
are underway already for the
2013 IEEE RFIC Symposium in Seattle, Washington, on June 2-4..
As such, a Call for Papers has gone out

In
December of 1931, the discovery of deuterium (aka 'heavy water)
was announced by Harold Urey, Japan abandoned the gold standard,
the New York Metropolitan Opera broadcasted an entire opera over
radio for the first time (on Christmas day), and the ARRL's QST
magazine published an article about how to improve a receiver by
using a screen-grid coupling stage on vacuum tubes. A 'tickler
coil' is introduced via a tuned circuit to provide a small amount
of positive feedback to the grid in order to make the amplifier
stage more sensitive in the band of interest. Care needed to be
taken to avoid so much feedback that oscillations could occur. As
with most of these old articles...

Linx
Technologies'
RF modules,
remote controls, evaluation kits and master development systems
feature straightforward hardware configuration and clear documentation,
making it simple for engineers and hobbyists to integrate wireless
features without the hassle and expense of engineering RF functionality
from scratch.

Vintage Electro-VoiceMicrophone Advertisement

Here
is an advertisement for
Electro-Voice Manufacturing Company microphones that I scanned
from page 101 of my copy of the February 1943 QST magazine.
As with many companies during the World War II era, this one's
theme is the service their products are providing to America's servicemen.
Per the ad, "If you were receiving radio messages from men in the
midst of ear­splitting battle noises, you'd hear crisp speech undistorted
by background sound effects. Electro-Voice Microphones, in military
service, are helping to make it possible. Similar microphones, designed
to achieve such results, will be available for specific commercial
applications ... after our wartime job is done..."

Thanks to Apex Wireless forTheir Continuing
Support

Since
1985, Apex Wireless has offered consulting, engineering, and design
services focusing on high-performance, cost-optimized products that
employ wireless RF transmitters, receivers, and transceivers. To
complement our
RF design expertise,
they work with local experts in DSP, ultra low power design, packaging,
certification, and manufacturing.

How to Draw a Circlewith a Square

"Squaring
the circle" may as yet be an unattainable goal for even the best
mathematicians, but the November 2012 edition of The Family Handyman
magazine had a tip for how to use a square
(of the framing type) and two nails to draw a circle. This
is what it said: "Make
a Circle with a Square - Here's a tip for laying out small circles
or parts of circles. Tack two nails to set the diameter you want,
then rotate a framing square against the nails while you hold a
pencil in the corner of the square. You might need to rub a little
wax or some other lubricant on the bottom of the square so it slides
easily. Don't ask us why this process works; all we know is that
it does." They're either very honest or they don't think the average
reader would understand the explanation. The Pythagorean theorem
is the key, of course, for explaining the reason. For any right
triangle: a2 + b2
= c2, where 'a' and
'b' are the lengths of the two perpendicular sides, and 'c' is the
length of the hypotenuse...

Tales from the Cube: Out-of-Spec Problem
with a Long Tail

I
like the artwork that usually accompanies these 'Tales from the
Cube' stories of troubleshooting prowess on the part of fellow engineers.
This installment, "Out-of-Spec
Problem with a Long Tail," reaches way back to the dawn of computer-based
circuit analysis to tell how a particularly troublesome problem
was solved by running a
Monte Carlo routine
to discover the culprit. Here is an explanation of a 'long-tail-pair
differential amplifier' in case you've never heard of it.

Many Thanks to Oscilentfor Continued Support

Oscilent
is a manufacturer of frequency control products offering design
and production expertise in SAW Filters, quartz crystals, crystal
oscillators & Filters, and ceramic resonators. Their product
line includes extensive custom and standard capabilities in TCXOs
and VCXOs, in addition to full design and development capabilities
in each focus product category. Oscilent serves OEM, design, and
CM customers in all major world development and manufacturing zones.

Science & Engineering ThemeCrossword
for 12/23/2012

For
the sake of avid cruciverbalists, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics,
chemistry, physics, and other technical words. You will never be
asked the name of a movie star unless he/she was involved in a technical
endeavor (e.g., Hedy Lamar).